Reactions of cumulated and conjugated dienes with sulfur trioxide
作者:Ruud M. Schonk、Bert H. Bakker、Hans Cerfontain
DOI:10.1002/recl.19931120301
日期:——
The reactions of a series of cumulated (1a-5a) and conjugated alkadienes (8a-13a) with sulfurtrioxide have been studied in the temperature range of −60 to 25°C using dichloromethane as solvent and 1.5 equiv of dioxane as reactivity moderator. Reaction of tetramethylallene (1a) at low temperature yielded the β-sultone 1b, which at 0°C was slowly converted into 2,4-dimethyl-1,3-pentadiene-3-sulfonic
Etude expérimentale et théorique de l'addition de l'acide hypochloreux sur les hydrocarbures alléniques
作者:J.-P. Bianchini、M. Cocordano
DOI:10.1016/s0040-4020(01)92917-5
日期:——
The addition of hypochlorous acid to allenic hydrocarbons leads, in all cases, to the fixation of the Cl atom on the central carbon and to the fixation of the OH group on the more substituted carbon. The (α-chloroketones which might be produced by the inverse fixation are not obtained. The utilisation of Hückel's method explains these results theoretically and satisfactorily.
The silyl-cupration and stannyl-cupration of allenes
作者:Ian Fleming、Michael Rowley、Purificacíon Cuadrado、Ana M. González-Nogal、Francisco J. Pulido
DOI:10.1016/0040-4020(89)80069-9
日期:1989.1
The stoichiometric silyl-cupration of allene 7, followed directly by treating the intermediate cuprate with a proton, with a range of carbon electrophiles, and with chlorine gives the vinylsilanes 8–13. Alternatively, when iodine is the electrophile, the product is the vinyl iodide 16. This can then be metallated and treated with a proton or a range of
Enantioselective photochemistry through Lewis acid–catalyzed triplet energy transfer
作者:Travis R. Blum、Zachary D. Miller、Desiree M. Bates、Ilia A. Guzei、Tehshik P. Yoon
DOI:10.1126/science.aai8228
日期:2016.12.16
spectroscopic data rule out substrate activation by means of photoinduced electron transfer and instead support a mechanism in which Lewisacid coordination dramatically lowers the triplet energy of the chalcone substrate. We expect that this approach will enable chemists to more broadly apply their detailed understanding of chiral Lewisacid catalysis to stereocontrol in reactions involving electronically excited